Friends, family, and colleagues are important sources for application discovery. Application installations and/or uses of applications are being increasingly shared among social and professional circles. The sharing of this information often serves application discovery, revealing which applications are popular in general or among different friends and social circles. Sharing application installation and usage information, however, generally raises privacy concerns. Even if a user does not generally mind sharing information regarding what applications the user has installed, there may be specific applications that are installed and/or used that the user may not wish others to know about (e.g., applications related to dating, pregnancy, medical issues, or the like).
Information regarding application usage is also increasingly being shared for the purposes of analytics and advertisement selection. Like sharing information with others, the sharing of application usage information also raises privacy concerns. Users may not wish that others (including third-party data collection analytics engines and advertisers) be aware of certain preferences or personal information (e.g., medical conditions).